ARMSTRONG WHITWORTH ROLLS LTD. v. MUSTARD Available to Purchase

December 2, 1970 Redundancy — Calculation of payment — “Normal working hours” — Consensual variation of contract of employment — Implication by conduct — Workman employed under contract of employment subject to national agreement — 40 hour week in five eight‐hour shifts — Subsequently told to work five 12‐hour shifts — No express mutual variation of contract — Natural inference to be drawn from working 12‐hour shifts thereafter for six years — Whether normal working hours increased — Contracts of Employment Act, 1963 (11 & 12 Eliz. II, c. 49) Sch. 1, para. 1(1) (2).